RE: Accessing signgam from the middle-end for builtin lgamma

["Dave Korn" <dave dot korn at artimi dot com>]

On 26 April 2007 16:26, Brian Dessent wrote:

> Dave Korn wrote:
> 
>> On 25 April 2007 18:55, Kaveh R. GHAZI wrote:
>> 
>>> I'd like to work on using MPFR to handle builtin lgamma.
>> 
>>   In what sense is it a builtin if it requires a library to be installed
>> and emits a call to a library function ???  I may not have understood what
>> you're trying to do here, but how would it be different from if the
>> compiler installed a header that said 
>> 
>> #define __builtin_lgamma lgamma /* Must have MPFR installed. */
> 
> The builtin would run on the host at compile time, whereas the above
> would run on the target at runtime.  I presume he's talking about using
> MPFR in the host compiler to simplify lgamma(constant), not actually
> causing any requirement on the target code to use or have MPFR.

  Oh, that makes sense.

  Kaveh, surely the answer is to just unconditionally emit something like

 (set (mem (sym_ref "_signgam")) (const_int VALUE)))

and let the user worry about what happens if they haven't included the correct
header file?


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....